Method and apparatus of corrugating



May 5, I970 J. 1'. YCVANOVICH METHOD AND APPARATUS OF CORRUGATING FiledNov. 10

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May 5, 1970 J. 'r. YOVANOVICH METHOD AND APPARATUS OF CORRUGATING 6Sheets-Sheet 6 Filed Nov. 10 1965 3,510,383 METHOD AND APPARATUS OFCORRUGATING Joseph T. Yovanovich, Rosemont, Pa., assignor to NationalTube and Reel Corporation, Belleville, N.J., a corporation of New JerseyFiled Nov. 10, 1965, Ser. No. 507,191 Int. 'Cl. B31f 1/00, 1/20 US. Cl.156462 8 Claims ABSTRACT OF THE DISCLOSURE This invention relatesgenerally to corrugating methods and apparatus.

It is an important object of the present invention to provide a highlyimproved apparatus for and method of corrugating relatively inextensiblesheet material without rupture or other damage to the sheet material.

It is still another object of the present invention to provide a uniquemethod and apparatus for producing corrugated sheet material wherein thecorrugations are of generally rectangular, or other nonroundcross-sectional configuration, in order to obtain increased strength ofthe corrugated sheet and greater adhesive holding power, all withoutdamage to the corrugated sheet.

It is still a further object of the present invention to provide aunique method of and apparatus for producing diagonal corrugations in anelongate sheet or web, and wherein plural diagonally corrugated sheetsmay be secured together to produce a stronger structure than heretoforepossible with the same materials.

The invention further contemplates the provision of corrugatingapparatus which is relatively simple in construction, durable andreliable throughout a long useful life, and which can be economicallymanufactured, maintained and operated for inexpensively producingcorrugated sheet.

Other objects of the present invention will become apparent upon readingthe following specification and referring to the accompanying drawings,which form a material part of this disclosure.

The invention accordingly consists in the features of construction,combinations and arrangements of parts and method steps, which will beexemplified in the following description and of which the scope will beindicated by the appended claims.

In the drawings:

FIG. 1 is a diagrammatic elevational view showing a conveyor line forproducing corrugated sheet in the final form of cloth boards;

FIG. 2 is a top plan view, somewhat enlarged, illustrating a section ofthe production line of FIG. 1;

FIG. 3 is an enlarged side elevational view showing the corrugatingapparatus of the present invention, partly broken for convenience inillustration;

FIG. 4 is a sectional elevational view taken generally along the line 44of FIG. 3, enlarged to illustrate greater detail;

FIG. 5 is a sectional elevational view taken generally along the line5-5 of FIG. 3, also enlarged;

FIG. 6 is a partial sectional elevational view taken generally along theline 6-6 of FIG. 3;

ni'tecl States: 0""

3,510,383 Patented May 5, 1970 FIG. 7 is a partial sectional View takengenerally along the line 7-7 of FIG. 6;

FIG. 8 is a top view of the apparatus of FIG. 3, as taken along the line8-8 of FIG. 3;

FIG. 9 is a horizontal sectional view taken generally along the line 99of FIG. 3;

FIG. 10 is a horizontal sectional view taken generally along the line1010 of FIG. 3;

FIG. 11 is a sectional view taken generally along the line 1111 of FIG.8;

FIG. 12 is a partial sectional view taken generally along the line 1212of FIG. 11;

FIG. 13 is a partial plan view of the apparatus shown in FIG. 11; and

FIG. 14 is a diagrammatic representation taken generally along the line1414 of FIG. 8.

Referring now more particularly to the drawings, and specifically toFIG. 1 thereof, there is illustrated therein a production line for themanufacture of cloth-board reels in accordance with the teachings of theinstant invention. In particular, the production line includescorrugating apparatus, generally designated 20, from which issue upperand lower corrugated sheets or webs 21 and 22, and an intermediate,generally flat sheet or web 23. The intermediate web 23 may pass throughan adhesive applicator 24 which applies adhesive to opposite faces ofthe intermediate sheet.

The corrugated sheets 21 and 22, with the web 23 sandwiched between thecorrugated sheets, pass together through a laminating station 25 wherethe corrugated sheets are moved into engagement with respectiveadhesive-coated surfaces of intermediate sheet 23. Issuing from thelaminating station 25 is a three-ply web or sheet 26, constituted of theupper and lower corrugated sheets 21 and 22, and intermediate web 23sandwiched between the corrugated sheets.

The sandwich structure, or built-up sheet 26 then passes to a wrappingstation 27, where a covering web or sheet 28 is passed longitudinallywith the sandwich structure 26 and through a wrapping or folding former29 to wrap the web 28 about the sandwich structure. The wrapper web 28may be supplied from a reel 29a over a roll 30 for movement thencelongitudinally with the sandwich structure 26 through the former 29. Thefolding of wrapper web 28 about the sandwich structure 26 is shown ingreater detail in FIG. 2. It will there be seen that oppositelongitudinal margins 31 and 32 of the wrapper web 28 are folded intooverlapping engagement, and may be adhesively secured together, as bypassage through a pressure securing station 33.

From the securing station 33, the wrapped sandwich structure 35 may passto a severance or cutoff station 36, from which may issue predeterminedlengths 37 of the board construction.

The corrugating apparatus 20 is best seen in FIGS. 3-5, as including abase or bottom support 40 extending longitudinally of the productionline. At the forward or inlet end of the corrugating apparatus 20, thereare a pair of laterally spaced, upstanding support walls or standards 41and 42 fixed on the base 40 by any suitable means. At the rear or outletend of the apparatus 20, upstanding from the base 40 are an additionalpair of support walls or standards 43 and 44, see FIG. 4. The front andrear support walls 41 and 43 are in alignment with each otherlongitudinally of the corrugating apparatus, while the front and rearsupport walls or standards 42 and 44 are in alignment with each otherlongitudinally of the corrugating apparatus.

An upper corrugating conveyor, generally designated 46 extendslongitudinally of the production line from a forward or inlet endbetween the support walls 41 and 42 to a rear or outlet end between thesupport walls 43 and 44. The upper corrugating conveyor 46 is spacedover the base 40, and a lower corrugating conveyor 47 is interposedbetween the base and upper corrugating conveyor. Thus, the lowercorrugating conveyor extends longitudinally of the production line froma forward or inlet end between the front support walls 41 and 42 to arear or outlet end between the rear support walls 43 and 44. The upperand lower corrugating conveyors 46 and 47 may extend generallyhorizontally in a longitudinal direction, and may be essentially similarin construction.

Intermediate the upper and lower corrugating conveyors 46 and 47 is agenerally horizontal, longitudinally extending web conveyor 48. The webconveyor 48 extends from a forward or inlet end between the frontsupport walls 41 and 42 and a rear or outlet end between the rearsupport walls 43 and 44.

Associated with each of the upper and lower corrugating conveyors 46 and47, and intermediate web conveyor 48, at the inlet ends thereof, is aweb or sheet guide for feeding a flexible sheet to the respectiveconveyor. In particular, an upper sheet guide 49 is arranged forward ofand adjacent to the inlet end of corrugating conveyor 46, while anintermediate sheet guide 50 is arranged forward of and adjacent to theinlet end of web conveyor 48, and a lower sheet guide 51 is arrangedadjacent to and forward of the inlet end of lower corrugating conveyor47.

The upper corrugating conveyor 46 includes a pair of upper and lowerendless bands or belts 54 and 55 of longitudinally elongateconfiguration, one above the other.

The upper endless band or belt 54 is trained about a pair of forward orfront wheels 56 and 57, respectively carried by supports 41 and 42, anda pair of rear wheels 58 and 59, respectively carried by rear supports43 and 44. The front wheels 56 and 57 are spaced horizontally forwardfrom the rear wheels 58 and 59, so that the belt 54 may be considered ashaving an upper or outer run 60 and lower or inner run 61.

The lower endless band or belt 55 of the upper corrugating conveyor 46is similarly trained about a pair of forward wheels 62 and 63respectively carried by the front support walls 41 and 42, and a pair ofrear wheels 64 and 65 respectively carried by the rear support walls 43and 44, and spaced horizontally rearward from the front wheels. Thelower endless band or conveyor 55 of the upper corrugating conveyor 46may then be considered as having a lower or outer run 66, and an upperor inner run 67. As best seen in FIG. 3, the inner runs 61 and 67 of theendless bands 54 and 55 extend longitudinally of the production line infacing relation with each other.

It will be observed, see FIG. 3, that the front wheels 56 and 62 aredirectly over each other, while the front wheels 57 and 63 are directlyover each other. Further, the front wheels 56 and 62 are spaced forwardof the front wheels 57 and 63, although all of the front wheels arerotatable about generally horizontal axes normal to the longitudinaldirection of conveyor movement. Thus, the band 54 in passing about thefront wheels 56 and 57 extends diagonally of the longitudinal directionof conveyor movement, approximately 45 degrees thereto. Similarly, theband 55, when passing about the front wheels 62 and 63 extendsdiagonally, approximately 45 degrees, relative to the longitudinaldirection of conveyor movement. The rear wheels 58 and 64 on one side ofthe corrugating conveyor 46 are similarly arranged one over the other,as are the rear wheels 59 and 65 on the other side of the conveyor.Further, the rear wheels 59 and 65 are spaced rearward of the rearwheels 58 and 64, so that the bands 54 and 55, when passing over therear wheels extend diagonally, approximately 45 degrees, with respect tothe longitudinal direction of conveyor movement.

The lower wheels 62, 63, 64 and 65 may be mounted by any suitable meansin their respective supporting walls 41, 42, 43 and 44; and if desired,provision may be made for adjustment of the Wheel-journaling means, sayhorizontally and/ or vertically. The upper wheels 56, 57, 58 and 59 arealso suitably carried by their respective supporting walls 41, 42, 43and 44, and provision is illustrated for vertical adjustment thereof.For example, a journal bearing 70 may rotatably receive the shaft 71 ofwheel 56, and may be carried by the wall support 41 in a vertical slot72 of the wall support. The journal bearing 70 may be carried at thelower end of a depending screw 73 which is connected by a meshingwormand-wheel mechanism 74 to a longitudinally extending rotary shaft75. The shaft 75 may be rotated by a handwheel 76 for effecting aselected vertical adjustment of conveyor-band Wheel 56.

The shaft 75 is carried by a journal bearing 69 on the wall support 41,and extends rotatably through an additional journal bearing 77 on thesupport wall 43 adjacent to the rear wheel 58. By similar worm-and-wheelmeans 78, see FIG. 6, the shaft 75 is connected to a depending screw 79which carries at its lower end a vertically adjustable journal bearing80 rotatably supporting the shaft 81 of rear wheel 58. By this meanssimultaneous vertical adjustment of wheels 56 and 58 is achieved uponrotation of shaft 75, as 'by handwheel 76.

In addition, the upper wheels 57 and 59 on the opposite side of theconveyor 46 may be similarly vertically adjusted. For example, see FIG.4, the rear wheel 59 may have its shaft 83 rotatably supported in ajournal member 84 which is carried at the lower end of a depending screw85 rotatably carried by support wall 44. The screw 85 may be connectedin positive driven relation with the screw 79, as by a chain 86 forsimultaneous movement of the screws. Also, the upper front wheel 57 maybe similarly mounted for vertical adjustment and connected forsimultaneous movement, as by a chain 87 from the depending screw 63. Itwill now be appreciated that the several wheels 56, 57, 58 and 59,supporting the upper corrugating-conveyor band 54, may be simultaneouslyvertically adjusted by rotation of the handwheel 76, say to move theinner runs 61 and 67 toward and away from each other. Alignment of theseveral wheels 56-59 in any selected position of their verticaladjustment may be insured by the provision of forwardly and rearwardlyextending constraining members 90 and 91, the former being connectedbetween the journal bearings of wheels 57 and 59, and the latter beingconnected between the journal bearings of wheels 56 and 58. In addition,the upper wheels 56-59 may be provided with means for horizontal,forward and rearward adjustment, if desired.

The upper band 54 may include a pair of endless chains 93 and 94, theformer being trained about the wheels 56 and 58, and in the latter beingtrained about the Wheels 57 and 59. The chains 93 and 94, and wheels5659 may be of conventional sprocket-type construction, with the chainspassing about the respective wheels on the pitch diameter thereof. Thus,the links of chains 93 and 94 always extend normal to their axes ofrotation and maintain a fixed spacing with respect to adjacent links.The chains 93 and 94 may be modified roller-sprocket chains, wherein asidepiece of each link may be provided with a mounting arm or bracket,as at 95 of chain 93 on the radially outer side thereof. The links ofchain 94 are similarly provided, on the radially outer side thereof,with mounting brackets 96. The mounting brackets 95 and 96 are thusdisposed generally normal to the radii of curvature of the respectivelink movement. On each mounting member or bracket 95 there is provided arotary member or swivel block 97 projecting outward from the respectivebracket 95 and connected to the latter by a pivot 98. The connectingpivot pin 98 of each swivel block 97 extends normal to the direction oflink movement, and thus along the radius of curvature of link movement.The outer end of each swivel block 97 is generally U shaped, as bestseen in FIG. 13, in the manner of a clevis receiving a crosspin 99extending between its legs.

Similarly, the mounting member or bracket 96 carried by each link ofchain 94 is disposed generally normal to the direction of link movement;and, a generally U- shaped or clevis-like swivel block 100 extendsnormal to and outward from each bracket 96, being connected thereto by apivot member or pin 101 extending along the radius of curvature of linkmovement. In addition, a pivot pin 102 may extend between the outer-endlegs of each swivel block 100.

In the manner of roller-sprocket chains, the links of chains 93 and 94maintain a constant spacing, and move along the pitch diameters of theirrespective sprocket wheels. However, the clevis-type swivel blocks 97and 100 project radially from the respective chain links beyond thepitch diameters thereof, so that the outer ends of adjacent swivelblocks are swung angularly away from each other upon movement alongcurved paths, as about sprocket wheels.

Extending laterally between the chains 93 and 94 are a plurality of barsor slats 105, each having its opposite ends connected to swivel blocksof respective chains; Thus, each slat or bar 105 has one end interposedbetween the legs of a swivel block 97, and connected thereto by its pin99, while the outer slat end is interposed between the legs of a swivelblock 100, and connected thereto by the associated pin 102. Further, theslats 105 extend between the chains 93 and 94 so as to pass about thefront wheels 56 and 57 generally parallel to a line connecting thecenters of the wheels, and similar relation with respect to the rearwheels 58 and 59.

It will now be appreciated that each slat 105 is connected at each endby a universal connection to one link of the respective adjacent chain93, 94. Specifically, the pins 99 and 98 of each swivel block 97 aredisposed normal to each other to define a universal connection betweeneach slat 105 and the chain 93, while normally disposed pins 101 and 102define a universal connection between each slat 105 and chain 94. Therespective chains are thus movable about their offset wheels, while theslats 105 are swingable relative to the chains to maintain connectiontherebetween upon continuous movement about the endless paths of thechains. As best seen in FIG. 8, the slots 105 extend diagonally,approximately 45" degrees, to the longitudinal direction of chainmovement. Further, as noted hereinbefore, the slats 105 will maintain asubstantial parallelism while moving along the upper and lower runs 60and 61 of the endless band 54, but will assume an increased angularspacing between adjacent slats upon their movement about the curvedpaths of the sprocket wheels. This variation in angular spacing betweenslats 105 is best illustrated in FIG. 14.

The lower endless band 55 of upper corrugating conveyor 46 may includechains similar to chains 93 and 94 and be provided with slats 107connected to the chains in the samemanner as slats 105. Further, as bestseen in FIG. 3, the slats 107 of band 55, when on the upper or inner runthereof, move in interdigitating or alternately interposed relation withrespect to the slats 105 on the lower or inner run of band 54. While intheir interdigitated relation, on the inner runs of bands 54 and 55, theslats 105 and 107 may have no relative movement, being moved at equalvelocities toward the outlet end of the corrugating conveyor. However,during movement of slats 105 and 107 into and out of theirinterdigitated relationship, as at the inlet and outlet ends of thecorrugating conveyor, there is relative movement between the slats of aparticular nature.

Referring to FIG. 14, it will appear that there is relative movementbetween adjacent slats 105 to reduce the angular spacing therebetween asthe slats move from the inlet wheels 56 and57 to the inner run 61. Thischange in relative angular spacing between the slats is re versed, orincreased, upon movement of the slats from the inner run 61 to theoutlet wheels 58 and 59. Similarly, the angular spacing between slats107 decreases as the slats move from the inlet wheels 62, 63 to theinner run 67, where the spacing remains constant, and thence increasesupon movement from the inner run to the outlet wheels 64 and 65. It isin the region of decreasing angular spacing between adjacent slats thata sheet or web 108 to be corrugated enters between the bands 54 and 55.While the sheet 108 may be of any desired material, it has been foundentirely practical to employ paper, cardboard, or the like, whichmaterials are readily subject to rupture. However, in the instantinvention the slats 105 engage with longitudinally spaced locations onone face of sheet 108 and effect simultaneous movement of the spacedlocations beyond the centerline or plane of the sheet toward thenonengaged surface while moving the spaced locations longitudinally ofthe sheet toward each other. This occurs simultaneously on the oppositeface of sheet 108 by the action of slats 107. Thus, by this action ofthe slats in engaging spaced locations of the sheet 108 and moving theselocations longitudinally of the sheet toward each other, whilesimultaneously depressing the sheet beyond its centerline or medianplane, it will be understood that the sheet is alternately bent orfolded in opposite directions to define corrugations, and that thebending or folding is accomplished with little or no relative movementof the slats with respect to the sheet at the points of engagement.Thus, forces tending to rupture or otherwise damage the sheet areeliminated or minimized.

The guide 49 for sheet 108 may be mounted by any suitable means at theinlet end of corrugating conveyor 46, as by a bracket 109 fixed to thesupport wall 41 and rotatably receiving the depending vertical shaft 110of an upstanding member 111. The guide 49 may include a pair oflaterally spaced side walls 112 and 113, which may be of generallyarcuate configuration, and a plurality of generally parallel rods 114may extend between and maintain the side members 112 in their fixedrelationship. A shaft 115 may extend from the sidepiece 112 into theupstanding mounting member 111, such that the guide 49 is adjustableboth about the vertical axis of rod 110 and horizontal axis of shaft115. The arcuate arrangement of crossrods 114 maintains the sheet 108 inan arcuate configuration for increased rigidity thereof to preventbuckling, and assures entry of the sheet between the bands 54 and 55 inan undefaced condition.

The lower corrugating conveyor 47 may be essentially the same as theupper corrugating conveyor 46, including a pair of upper and lowerendless bands or belts and 121, the former carrying outwardly projectingslats 122, and the latter carrying outwardly projecting slats 123. Thebelts 120 and 121 may be mounted in essentially the same manner as thebelts 54 and 55, suitable provision for adjustment being made, ifdesired. Further, the interrelationship between the slats 122 and 123may be substantially identical to the interrelationship between slats105 and 107. However, in the illustrated embodiment it is preferred thatthe slats 122 and 123 extend diagonally in the opposite direction withrespect to the longitudinal dimension as the slats 105 and 107. Hence,the corrugations formed by-the upper corrugating conveyor 46 extend inone direction diagonally of the longitudinal, while the corrugationsformed by the lower corrugating conveyor 47 extend in another diagonaldirection, as seen in FIG. 2.

Also, the sheet guide 51 may be essentially identical to the sheet guide49, but is advantageously adjusted for feeding a sheet at an oppositeangle of inclination, corper and lower corrugating conveyors 46 and 47..The intermediate conveyor 48 may include a pair of upper and lower entrywheels 125 and 126 mounted for rotation about generally horizontal axes,and a pair of upper and lower exit wheels 127 and 128, also mounted forrotation about horizontal axes. Trained about the upper entry wheel 125and upper exit wheel 127 may be an endless flexible band or belt 129,and an additional endless flexible band or belt 130 may be trained aboutthe lower entry wheel 126 and lower exit wheel 128. The belts 129 and130 include inner runs in facing engagement with each other and aremovable to convey a web 131 between the inner runs for discharge frombetween the exit rolls 127 and 128.

The sheet feed guide 50 may be substantially identical to the guides 49and 51, but is arranged in alignment with the longitudinal direction offeeding, as the intermediate sheet 131 is not diagonally corrugated, orcorrugated at all.

In order to drive the corrugating conveyors 46 and 47, and intermediateweb conveyor 48, there may be provided a horizontal drive shaft 135connected by bevel gears 136 and 137 to a shaft 138. The shaft 138 maybe connected in driving relation by a chain 139 with the shaft of exitroll 128 of the intermediate conveyor. A spur gear 140 is carried on theshaft 138 for meshing engagement with a spur gear 141, the latter beingcarried by a shaft 142 and connected by a drive chain 143 to the shaftof upper exit roller 127 of the intermediate conveyor. The lower band 55of the upper corrugating conveyor is driven by a spur gear 145 on theshaft 146 of wheel 65; and, a spur gear 147 in meshing engagement withgear 145 is carried by the shaft of wheel 59.

The wheels 64 and 58 are similarly positively driven, as are the rear ordischarge-end wheels of the lower corrugating conveyor 47, to insureproperly synchronized motion of all parts.

From the foregoing, it is seen that the present invention provides aunique and highly advantageous method of corrugating and apparatustherefor which fully ac complish their intended objects and are welladapted to meet practical conditions of manufacture and use.

What is claimed is:

1. A corrugating apparatus comprising a pair of endless bands eachtrained about inlet and outlet wheels and having inner and outer runswith the inner runs of respective bands being in longitudinallyextending facing relation, motive means for moving said bands abouttheir endless paths at equal linear velocities, a plurality of rigidslats carried by each of said bands extending obliquely thereacross andmovable therewith into interdigitating relaiton with the slats of theother band upon passage about said inlet wheels to said inner runs andout of said interdigitating relation upon passage from said inner runsabout said outlet wheels, and universal mounting means mounting eachslat on its respective band at a generally constant angle relativethereto, the slats of each band moving between increased angular spacingalong said wheels and decreased angular spacing along said runs, wherebya sheet to be corrugated entering between said inlet wheels is engagedon opposite surfaces by slats of respective bands moving towarddecreased angular spacing to gather the sheet material and effectcorrugation with minimum relative movement between slats and sheet.

2. A corrugating apparatus according to claim 1, said bands eachcomprising chain means having a pitch diameter equal to the pitchdiameter of the respective inlet wheel, said slats projecting fromrespective chains outwardly beyond the pitch diameters thereof atsubstantially constant angle thereto, whereby said slats are radiallyseparated upon movement along said inlet wheels.

3. A corrugating apparatus according to claim 1, said slats having theirprojecting portions of generally rectangular cross-sectionalconfiguration to define corrugations of generally rectangular formation.

4. A corrugating apparatus according to claim 1, said bands eachcomprising a pair of endless members located in longitudinally offsetrelation along the path of sheet movement, and said slats extendingbetween corresponding locations on said endless members, whereby theangle of offset of said endless members defines the obliqu dispositionof said slats.

5. A corrguating apparatus according to claim 4, said chain means eachcomprising a pair of laterally spaced chains extending about respectiveinlet and outlet wheels, said slats extending between said pair ofchains for movement therewith at a substantially constant angle thereto.

6. A corrugating apparatus according to claim 5, the chains of each bandand associated wheels being offset longitudinally of the direction ofsheet movement to determine the oblique disposition of said slats.

7. A corrugating apparatus comprising a pair of endless bands eachtrained about inlet and outlet wheels and having inner and outer runswith the inner runs of respective bands being in longitudinallyextending facing relation, motive means for moving said bands abouttheir endless paths at equal linear velocities, a plurality of slatscarried by each of said bands extending transversely there across andmovable therewith into interdigitating relation with the slats of theother band upon passage about said inlet wheels to said inner runs andout of said interdigitating relation upon passage from said inner runsabout said outlet wheels, the slats of each band moving betweenincreased angular spacing along said wheels and decreased angularspacing along said runs, for corrugating a sheet entering between saidinlet wheels by engaging the sheet on opposite surfaces with slats ofrespective bands moving toward decreased angular spacing to effectcorrugation with minimum relative movement between slats and sheet, aweb conveyor for conveying a web into adhesive engagement with one sideof a corrugated sheet emerging from between said pair of bands, a secondpair of endless bands each trained about respective inlet and outletwheels and having inner and outer runs with the inner runs of respectivebands in longitudinally extending facing relation, a plurality of slatscarried by each of said second pair of bands extending transverselythere across and movable therewith into interdigitating relation withthe slats of the other of said second pair of bands upon passage aboutrespective inlet wheels to the inner runs of said second pair of bandsand out of said interdigitating relation upon passage from the innerruns of said second pair of bands about respective outlet wheels, theslats of each second pair of bands moving between increased angularspacing along respective wheels and decreased angular spacing alongrespective runs, for corrugating a second sheet passing between saidsecond pair of bands, and means for adhesively engaging a corrugatedsheet emerging from between said second pair of bands with a web fromsaid web conveyor on the opposite side of said web as the corrugatedsheet from said first pair of bands.

8. A corrugating apparatus according to claim 7, the slats of said firstpair of bands extending in one direction diagonally with respective tothe direction of sheet movement between said bands, and the slats ofsaid second pair of bands extending diagonally in the other directionwith respect to the direction of sheet movement between said bands,whereby corrguated sheets emerging from between said first and secondpairs of bands have their corrugations extending diagonally in oppositedirections.

References Cited UNITED STATES PATENTS 1,650,050 11/1927 Smith 93-11,931,365 10/1933 Watson 156591XR (Other references on following page)References Cited UNITED STATES PATENTS Palmer 156592 XR Kappler 156-591XR Burrill 156-471 Andreoli et a1. 156206 Wells et a1. 161137 Granozio156-471 Hecker 156471 10 JOHN T. GOOLKASIAN, Primary Examiner D. I.FRITSCH, Assistant Examiner US. Cl. X.R.

